Method for managing throughput in a distributed storage network

ABSTRACT

A method for managing throughput in a distributed storage network includes encoding data to produce a plurality of sets of encoded data slices. According to the method, one or more write slice requests are generated corresponding to one or more sets of encoded data slices, and write slice requests are then output to a set of distributed storage and task execution units. For each distributed storage and task execution unit, a data ingest rate is generated and a write threshold number of distributed storage and task execution units is determined. A transmit data rate is determined and write slice requests are determined, followed by the generation write slice requests to the distributed storage and task execution units. A write threshold number of write slice requests is then input to the distributed storage and task execution units.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present U.S. Utility patent application claims priority pursuant to 35 U.S.C. §120 as a continuation-in-part of U.S. Utility application Ser. No. 13/917,017, entitled “ENCRYPTING SEGMENTED DATA IN A DISTRIBUTED COMPUTING SYSTEM,” filed Jun. 13, 2013, which is a continuation-in-part of U.S. Utility application Ser. No. 13/707,428, entitled “DISTRIBUTED COMPUTING IN A DISTRIBUTED STORAGE AND TASK NETWORK,” filed Dec. 6, 2012, now U.S. Pat. No. 9,298,548, which claims priority pursuant to 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/569,387, entitled “DISTRIBUTED STORAGE AND TASK PROCESSING,” filed Dec. 12, 2011, all of which are hereby incorporated herein by reference in their entirety and made part of the present U.S. Utility patent application for all purposes.

U.S. Utility patent application Ser. No. 13/917,017 claims priority pursuant to 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/679,007, entitled “TASK PROCESSING IN A DISTRIBUTED STORAGE AND TASK NETWORK,” filed Aug. 2, 2012, all of which are hereby incorporated herein by reference in their entirety and made part of the present U.S. Utility patent application for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

Technical Field of the Invention

This invention relates generally to computer networks and more particularly to dispersing error encoded data.

Description of Related Art

Computing devices are known to communicate data, process data, and/or store data. Such computing devices range from wireless smart phones, laptops, tablets, personal computers (PC), work stations, and video game devices, to data centers that support millions of web searches, stock trades, or on-line purchases every day. In general, a computing device includes a central processing unit (CPU), a memory system, user input/output interfaces, peripheral device interfaces, and an interconnecting bus structure.

As is further known, a computer may effectively extend its CPU by using “cloud computing” to perform one or more computing functions (e.g., a service, an application, an algorithm, an arithmetic logic function, etc.) on behalf of the computer. Further, for large services, applications, and/or functions, cloud computing may be performed by multiple cloud computing resources in a distributed manner to improve the response time for completion of the service, application, and/or function. For example, Hadoop is an open source software framework that supports distributed applications enabling application execution by thousands of computers.

In addition to cloud computing, a computer may use “cloud storage” as part of its memory system. As is known, cloud storage enables a user, via its computer, to store files, applications, etc. on an Internet storage system. The Internet storage system may include a RAID (redundant array of independent disks) system and/or a dispersed storage system that uses an error correction scheme to encode data for storage.

Dispersed storage networks are made up of a plurality of distributed storage and task (DST) clients, each of which may simultaneously receive data, encode data to produce slices, and send slices to a set of DST execution units for storage of the data. Each DST execution unit may be associated with a unique slice ingest rate as compared to slice ingest rates of other DST execution units. The dispersed storage network may include processing units capable of managing the varying slice ingest rate to improve the efficiency of the network.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a dispersed or distributed storage network (DSN) in accordance with the present invention;

FIG. 2 is a schematic block diagram of an embodiment of a computing core in accordance with the present invention;

FIG. 3 is a schematic block diagram of an example of dispersed storage error encoding of data in accordance with the present invention;

FIG. 4 is a schematic block diagram of a generic example of an error encoding function in accordance with the present invention;

FIG. 5 is a schematic block diagram of a specific example of an error encoding function in accordance with the present invention;

FIG. 6 is a schematic block diagram of an example of a slice name of an encoded data slice (EDS) in accordance with the present invention;

FIG. 7 is a schematic block diagram of an example of dispersed storage error decoding of data in accordance with the present invention;

FIG. 8 is a schematic block diagram of a generic example of an error decoding function in accordance with the present invention;

FIG. 9A is a schematic block diagram of another embodiment of a distributed computing system in accordance with the present invention;

FIG. 9B is a flowchart illustrating an example of storing data in accordance with the present invention;

FIG. 10 is a flowchart illustrating another example of storing data in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of an embodiment of a dispersed, or distributed, storage network (DSN) 10 that includes a plurality of computing devices 12-16, a managing unit 18, an integrity processing unit 20, and a DSN memory 22. The components of the DSN 10 are coupled to a network 24, which may include one or more wireless and/or wire lined communication systems; one or more non-public intranet systems and/or public internet systems; and/or one or more local area networks (LAN) and/or wide area networks (WAN).

The DSN memory 22 includes a plurality of storage units 36 that may be located at geographically different sites (e.g., one in Chicago, one in Milwaukee, etc.), at a common site, or a combination thereof. For example, if the DSN memory 22 includes eight storage units 36, each storage unit is located at a different site. As another example, if the DSN memory 22 includes eight storage units 36, all eight storage units are located at the same site. As yet another example, if the DSN memory 22 includes eight storage units 36, a first pair of storage units are at a first common site, a second pair of storage units are at a second common site, a third pair of storage units are at a third common site, and a fourth pair of storage units are at a fourth common site. Note that a DSN memory 22 may include more or less than eight storage units 36. Further note that each storage unit 36 includes a computing core (as shown in FIG. 2, or components thereof) and a plurality of memory devices for storing dispersed error encoded data.

Each of the computing devices 12-16, the managing unit 18, and the integrity processing unit 20 include a computing core 26, which includes network interfaces 30-33. Computing devices 12-16 may each be a portable computing device and/or a fixed computing device. A portable computing device may be a social networking device, a gaming device, a cell phone, a smart phone, a digital assistant, a digital music player, a digital video player, a laptop computer, a handheld computer, a tablet, a video game controller, and/or any other portable device that includes a computing core. A fixed computing device may be a computer (PC), a computer server, a cable set-top box, a satellite receiver, a television set, a printer, a fax machine, home entertainment equipment, a video game console, and/or any type of home or office computing equipment. Note that each of the managing unit 18 and the integrity processing unit 20 may be separate computing devices, may be a common computing device, and/or may be integrated into one or more of the computing devices 12-16 and/or into one or more of the storage units 36.

Each interface 30, 32, and 33 includes software and hardware to support one or more communication links via the network 24 indirectly and/or directly. For example, interface 30 supports a communication link (e.g., wired, wireless, direct, via a LAN, via the network 24, etc.) between computing devices 14 and 16. As another example, interface 32 supports communication links (e.g., a wired connection, a wireless connection, a LAN connection, and/or any other type of connection to/from the network 24) between computing devices 12 and 16 and the DSN memory 22. As yet another example, interface 33 supports a communication link for each of the managing unit 18 and the integrity processing unit 20 to the network 24.

Computing devices 12 and 16 include a dispersed storage (DS) client module 34, which enables the computing device to dispersed storage error encode and decode data (e.g., data 40) as subsequently described with reference to one or more of FIGS. 3-8. In this example embodiment, computing device 16 functions as a dispersed storage processing agent for computing device 14. In this role, computing device 16 dispersed storage error encodes and decodes data on behalf of computing device 14. With the use of dispersed storage error encoding and decoding, the DSN 10 is tolerant of a significant number of storage unit failures (the number of failures is based on parameters of the dispersed storage error encoding function) without loss of data and without the need for a redundant or backup copies of the data. Further, the DSN 10 stores data for an indefinite period of time without data loss and in a secure manner (e.g., the system is very resistant to unauthorized attempts at accessing the data).

In operation, the managing unit 18 performs DS management services. For example, the managing unit 18 establishes distributed data storage parameters (e.g., vault creation, distributed storage parameters, security parameters, billing information, user profile information, etc.) for computing devices 12-14 individually or as part of a group of user devices. As a specific example, the managing unit 18 coordinates creation of a vault (e.g., a virtual memory block associated with a portion of an overall namespace of the DSN) within the DSN memory 22 for a user device, a group of devices, or for public access and establishes per vault dispersed storage (DS) error encoding parameters for a vault. The managing unit 18 facilitates storage of DS error encoding parameters for each vault by updating registry information of the DSN 10, where the registry information may be stored in the DSN memory 22, a computing device 12-16, the managing unit 18, and/or the integrity processing unit 20.

The managing unit 18 creates and stores user profile information (e.g., an access control list (ACL)) in local memory and/or within memory of the DSN memory 22. The user profile information includes authentication information, permissions, and/or the security parameters. The security parameters may include encryption/decryption scheme, one or more encryption keys, key generation scheme, and/or data encoding/decoding scheme.

The managing unit 18 creates billing information for a particular user, a user group, a vault access, public vault access, etc. For instance, the managing unit 18 tracks the number of times a user accesses a non-public vault and/or public vaults, which can be used to generate a per-access billing information. In another instance, the managing unit 18 tracks the amount of data stored and/or retrieved by a user device and/or a user group, which can be used to generate a per-data-amount billing information.

As another example, the managing unit 18 performs network operations, network administration, and/or network maintenance. Network operations includes authenticating user data allocation requests (e.g., read and/or write requests), managing creation of vaults, establishing authentication credentials for user devices, adding/deleting components (e.g., user devices, storage units, and/or computing devices with a DS client module 34) to/from the DSN 10, and/or establishing authentication credentials for the storage units 36. Network administration includes monitoring devices and/or units for failures, maintaining vault information, determining device and/or unit activation status, determining device and/or unit loading, and/or determining any other system level operation that affects the performance level of the DSN 10. Network maintenance includes facilitating replacing, upgrading, repairing, and/or expanding a device and/or unit of the DSN 10.

The integrity processing unit 20 performs rebuilding of ‘bad’ or missing encoded data slices. At a high level, the integrity processing unit 20 performs rebuilding by periodically attempting to retrieve/list encoded data slices, and/or slice names of the encoded data slices, from the DSN memory 22. For retrieved encoded slices, they are checked for errors due to data corruption, outdated version, etc. If a slice includes an error, it is flagged as a ‘bad’ slice. For encoded data slices that were not received and/or not listed, they are flagged as missing slices. Bad and/or missing slices are subsequently rebuilt using other retrieved encoded data slices that are deemed to be good slices to produce rebuilt slices. The rebuilt slices are stored in the DSN memory 22.

FIG. 2 is a schematic block diagram of an embodiment of a computing core 26 that includes a processing module 50, a memory controller 52, main memory 54, a video graphics processing unit 55, an input/output (IO) controller 56, a peripheral component interconnect (PCI) interface 58, an 10 interface module 60, at least one IO device interface module 62, a read only memory (ROM) basic input output system (BIOS) 64, and one or more memory interface modules. The one or more memory interface module(s) includes one or more of a universal serial bus (USB) interface module 66, a host bus adapter (HBA) interface module 68, a network interface module 70, a flash interface module 72, a hard drive interface module 74, and a DSN interface module 76.

The DSN interface module 76 functions to mimic a conventional operating system (OS) file system interface (e.g., network file system (NFS), flash file system (FFS), disk file system (DFS), file transfer protocol (FTP), web-based distributed authoring and versioning (WebDAV), etc.) and/or a block memory interface (e.g., small computer system interface (SCSI), internet small computer system interface (iSCSI), etc.). The DSN interface module 76 and/or the network interface module 70 may function as one or more of the interface 30-33 of FIG. 1. Note that the IO device interface module 62 and/or the memory interface modules 66-76 may be collectively or individually referred to as IO ports.

FIG. 3 is a schematic block diagram of an example of dispersed storage error encoding of data. When a computing device 12 or 16 has data to store it disperse storage error encodes the data in accordance with a dispersed storage error encoding process based on dispersed storage error encoding parameters. The dispersed storage error encoding parameters include an encoding function (e.g., information dispersal algorithm, Reed-Solomon, Cauchy Reed-Solomon, systematic encoding, non-systematic encoding, on-line codes, etc.), a data segmenting protocol (e.g., data segment size, fixed, variable, etc.), and per data segment encoding values. The per data segment encoding values include a total, or pillar width, number (T) of encoded data slices per encoding of a data segment (i.e., in a set of encoded data slices); a decode threshold number (D) of encoded data slices of a set of encoded data slices that are needed to recover the data segment; a read threshold number (R) of encoded data slices to indicate a number of encoded data slices per set to be read from storage for decoding of the data segment; and/or a write threshold number (W) to indicate a number of encoded data slices per set that must be accurately stored before the encoded data segment is deemed to have been properly stored. The dispersed storage error encoding parameters may further include slicing information (e.g., the number of encoded data slices that will be created for each data segment) and/or slice security information (e.g., per encoded data slice encryption, compression, integrity checksum, etc.).

In the present example, Cauchy Reed-Solomon has been selected as the encoding function (a generic example is shown in FIG. 4 and a specific example is shown in FIG. 5); the data segmenting protocol is to divide the data object into fixed sized data segments; and the per data segment encoding values include: a pillar width of 5, a decode threshold of 3, a read threshold of 4, and a write threshold of 4. In accordance with the data segmenting protocol, the computing device 12 or 16 divides the data (e.g., a file (e.g., text, video, audio, etc.), a data object, or other data arrangement) into a plurality of fixed sized data segments (e.g., 1 through Y of a fixed size in range of Kilo-bytes to Tera-bytes or more). The number of data segments created is dependent of the size of the data and the data segmenting protocol.

The computing device 12 or 16 then disperse storage error encodes a data segment using the selected encoding function (e.g., Cauchy Reed-Solomon) to produce a set of encoded data slices. FIG. 4 illustrates a generic Cauchy Reed-Solomon encoding function, which includes an encoding matrix (EM), a data matrix (DM), and a coded matrix (CM). The size of the encoding matrix (EM) is dependent on the pillar width number (T) and the decode threshold number (D) of selected per data segment encoding values. To produce the data matrix (DM), the data segment is divided into a plurality of data blocks and the data blocks are arranged into D number of rows with Z data blocks per row. Note that Z is a function of the number of data blocks created from the data segment and the decode threshold number (D). The coded matrix is produced by matrix multiplying the data matrix by the encoding matrix.

FIG. 5 illustrates a specific example of Cauchy Reed-Solomon encoding with a pillar number (T) of five and decode threshold number of three. In this example, a first data segment is divided into twelve data blocks (D1-D12). The coded matrix includes five rows of coded data blocks, where the first row of X11-X14 corresponds to a first encoded data slice (EDS 1_1), the second row of X21-X24 corresponds to a second encoded data slice (EDS 2_1), the third row of X31-X34 corresponds to a third encoded data slice (EDS 3_1), the fourth row of X41-X44 corresponds to a fourth encoded data slice (EDS 4_1), and the fifth row of X51-X54 corresponds to a fifth encoded data slice (EDS 5_1). Note that the second number of the EDS designation corresponds to the data segment number.

Returning to the discussion of FIG. 3, the computing device also creates a slice name (SN) for each encoded data slice (EDS) in the set of encoded data slices. A typical format for a slice name 80 is shown in FIG. 6. As shown, the slice name (SN) 80 includes a pillar number of the encoded data slice (e.g., one of 1-T), a data segment number (e.g., one of 1-Y), a vault identifier (ID), a data object identifier (ID), and may further include revision level information of the encoded data slices. The slice name functions as, at least part of, a DSN address for the encoded data slice for storage and retrieval from the DSN memory 22.

As a result of encoding, the computing device 12 or 16 produces a plurality of sets of encoded data slices, which are provided with their respective slice names to the storage units for storage. As shown, the first set of encoded data slices includes EDS 1_1 through EDS 5_1 and the first set of slice names includes SN 1_1 through SN 5_1 and the last set of encoded data slices includes EDS 1_Y through EDS 5_Y and the last set of slice names includes SN 1_Y through SN 5_Y.

FIG. 7 is a schematic block diagram of an example of dispersed storage error decoding of a data object that was dispersed storage error encoded and stored in the example of FIG. 4. In this example, the computing device 12 or 16 retrieves from the storage units at least the decode threshold number of encoded data slices per data segment. As a specific example, the computing device retrieves a read threshold number of encoded data slices.

To recover a data segment from a decode threshold number of encoded data slices, the computing device uses a decoding function as shown in FIG. 8. As shown, the decoding function is essentially an inverse of the encoding function of FIG. 4. The coded matrix includes a decode threshold number of rows (e.g., three in this example) and the decoding matrix in an inversion of the encoding matrix that includes the corresponding rows of the coded matrix. For example, if the coded matrix includes rows 1, 2, and 4, the encoding matrix is reduced to rows 1, 2, and 4, and then inverted to produce the decoding matrix.

FIG. 9A is a schematic block diagram of another embodiment of a distributed computing system that includes a plurality of distributed storage and task (DST) processing units 16 and a distributed storage and task network (DSTN) module 22. Each DST processing unit 16 of the plurality of DST processing units 16 includes an interface 30, a DST client module 34, and an interface 32. The DSTN module 22 includes a set of DST execution units 36. For example, the DSTN module 22 includes five DST execution units 36 when a pillar width is five.

The system functions to store data as a plurality of sets of encoded data slices in the DSTN module 22. The data may be retrieved from the DSTN module 22 when at least a decode threshold number of encoded data slices per set of the plurality of sets of encoded data slices is available. A DST client module 34 receives the data via the interface 30 and encodes the data to produce the plurality of sets of encoded data slices for storage in at least a decode threshold number of DST execution units 36 of the set of DST execution units 36.

Each DST client module 34 of the plurality of DST processing unit 16 may simultaneously receive data, encode the data to produce slices, and send slices to the set of DST execution units 36 for storage therein. Each DST execution unit 36 may be associated with a unique slice ingest rate as compared to slice ingest rates of other DST execution units 36. Each DST client module 34 may determine a write threshold when storing data in the DSTN module 22 based on slice ingest rates of the set of DST execution units 36. The write threshold is greater than or equal to the decode threshold and less than or equal to the pillar width. For example, the DST client module 34 determines the write threshold to be 4 based on a current slice ingest rate of the set of DST execution units 36 when the decode threshold is 3 and the pillar width is 5. In such an example, the DST client module 34 sends 4 slices per set of the plurality of sets of encoded data slices to four of the DST execution units 36 for storage therein.

In an example of operation, the DST client module 34 of a first DST processing unit 16 receives data via interface 30 and encodes the data to produce the plurality of sets of encoded data slices. The DST client module 34 determines the write threshold based on one or more of a reliability level goal, a speed threshold goal, an ingest rate of the data, a predetermination, a look up, a request, a query, a test, and input/output load placed on the set of DST execution units 36 by one or more other DST processing units 16, and an ingest rate associated with each DST execution unit 36 of the set of DST execution units 36. For example, the DST client module 34 sends a first set of encoded data slices to the set of DST execution units 36 and monitors ingestion performance to determine the ingest rate capability associated with each DST execution unit 36. For instance, a first DST execution unit 36 ingests pillar 1 slices at a rate of 90 MB per second, a second DST execution unit 36 ingests pillar 2 slices at a rate of 100 MB per second, a third DST execution unit 36 ingests pillar 3 slices at a rate of 85 MB per second, a fourth DST execution unit 36 ingests pillar 4 slices at a rate of 80 MB per second, and a fifth DST execution unit 36 ingests pillar 5 slices at a rate of 70 MB per second. Next, the DST client module 34 selects the write threshold to be three and determines to utilize the first, the second, and the third DST execution unit 36 to ingest the read threshold number of encoded data slices per set of encoded data slices since those DST execution units 36 have a most favorable ingestion rate capability level.

As another example, DST client module 34 obtains input/output load information from other DST processing unit 16 of the plurality of DST processing units 16 to determine available access capacity of each DST execution unit 36. The method of operation of the DST client module 34 where this example is discussed in greater detail with reference to FIG. 41.

The DST client module 34 sends the write threshold number of encoded data slices per set of encoded data slices to a corresponding write threshold number of DST execution units 36 of the set of DST execution units 36. The DST client module 34 may facilitate rebuilding of other encoded data slices per set of encoded data slices, wherein the other encoded data slices were not written to corresponding DST execution units 36.

FIG. 9B is a flowchart illustrating an example of storing data. The method begins at the step where a processing module (e.g., of a distributed storage and task (DST) client module) encodes data to produce a plurality of sets of encoded data slices utilizing a dispersed storage error coding function. The method continues at the step where the processing module generates one or more sets of write slice requests that includes a corresponding one or more sets of encoded data slices of the plurality of sets of encoded data slices. The generating may include determining the number of the one or more sets of write slice requests based on at least one of a predetermination, a historic number to realize reliable ingest speed data, and a request. For example, the processing module determines to send five sets of encoded data slices when reliable ingest speed data has been historically obtained utilizing four sets of encoded data slices.

The method continues at the step where the processing module outputs the one more sets of write slice requests to a set of DST execution units. For each DST execution unit of a set of DST execution units, the method continues at the step where the processing module determines a data ingest rate of a set of data ingest rates. The determining may be based on one or more of a query, a speed test, a lookup, and receiving an error message.

The method continues at the step where the processing module determines a write threshold number of DST execution units of the set of DST execution units based on the set of data ingest rates. The determining may be further based on one or more of an estimated reliability level for data storage, a reliability level threshold, an estimated access speed, a lowest access speed of the write threshold number of DST execution units, a speed threshold, an access capability estimator, a predetermination, an estimated rebuilding impact, a rebuilding impact threshold, and a lookup. For example, a processing module determines to utilize a first, a third, a fourth and a fifth DST execution unit of the set of DST execution units to realize the write threshold of four for a set of five DST execution units, when the first, the third, the fourth, and the fifth DST execution unit each have an estimated access speed greater than the speed threshold, and the estimated rebuilding impact compares favorably to the rebuilding impact threshold for rebuilding slices of a second DST execution unit of the set of DST execution units.

The method continues at the step where the processing module determines a transmit data rate such that the transmit data rate compares favorably (e.g., greater than or equal to) to a lowest data ingest rate of the write threshold number of DST execution units. For example, the processing module determines the transmit data rate to be 70 MB per second when the lowest data ingest rate of the write threshold number of DST execution units is 70 MB per second.

For each remaining set of encoded data slices of the plurality of sets of encoded data slices, the method continues at the step where the processing module generates a write threshold number of write slice requests, wherein each request includes a corresponding encoded data slice of a write threshold number of encoded data slices. For example, the processing module generates write slice requests for pillars one, three, four, and five when DST execution units one, three, four, and five have been selected as part of the write threshold number of DST execution units.

The method continues at the step where the processing module outputs the write threshold number of write slice requests to the write threshold number of DST execution units of the set of DST execution units in accordance with the transmit data rate. For example, the processing module outputs slices to each of the write threshold number of DST execution units at a rate of 70 MB per second when the transmit data rate is 70 MB per second. The for each of the remaining sets of encoded data slices of the plurality of sets of encoded data slices, the method continues at the step where the processing module facilitates rebuilding other encoded data slices (e.g., slices not written). The facilitating includes at least one of directly rebuilding, rebuilding in accordance with a schedule to achieve a loading goal, and sending a rebuilding request to a rebuilding module.

FIG. 10 is a flowchart illustrating another example of storing data. The method begins at the step where a processing module (e.g., of a distributed storage and task (DST) client module of a DST processing unit) determines to access a set of DST execution units with regards to data that is encoded to produce a plurality of sets of encoded data slices. Accessing includes at least one of reading a slice and writing a slice. The determining may be based on one or more of receiving a retrieval request, receiving a rebuilding request, and receiving a storage request.

For each other DST processing unit of a plurality of DST processing units that includes the DST processing unit, the method continues at the step where the processing module determines a data loading level for the set of DST execution units. The data loading level includes input and/or output loading metrics for access to each DST execution unit of the set of DST execution units with regards to the DST processing unit. The determining may be based on one or more of a query, a test, monitoring loading levels, receiving a list, and receiving loading information as part of an access request. For example, the processing module queries for DST processing units for a data loading level with regards to the set of DST execution units when the processing module determines that five DST processing units are accessing the set of DST execution units, wherein the five DST processing units includes the DST processing unit.

The method continues at the step where the processing module determines an access rate based on the plurality of data loading levels. The processing module determines the access rate such that the access rate plus an aggregate of the plurality of data loading levels is less than an access capability level of the set of DST execution units. The method continues at the step where the processing module determines an excess threshold number of DST execution units of the set of DST execution units based on access rate. The determining includes identifying a loading level for each DST execution unit in determining the access threshold number by dividing the access rate by a lowest loading level of a set of loading levels.

It is noted that terminologies as may be used herein such as bit stream, stream, signal sequence, etc. (or their equivalents) have been used interchangeably to describe digital information whose content corresponds to any of a number of desired types (e.g., data, video, speech, audio, etc. any of which may generally be referred to as ‘data’).

As may be used herein, the terms “substantially” and “approximately” provides an industry-accepted tolerance for its corresponding term and/or relativity between items. Such an industry-accepted tolerance ranges from less than one percent to fifty percent and corresponds to, but is not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, and/or thermal noise. Such relativity between items ranges from a difference of a few percent to magnitude differences. As may also be used herein, the term(s) “configured to”, “operably coupled to”, “coupled to”, and/or “coupling” includes direct coupling between items and/or indirect coupling between items via an intervening item (e.g., an item includes, but is not limited to, a component, an element, a circuit, and/or a module) where, for an example of indirect coupling, the intervening item does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As may further be used herein, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two items in the same manner as “coupled to”. As may even further be used herein, the term “configured to”, “operable to”, “coupled to”, or “operably coupled to” indicates that an item includes one or more of power connections, input(s), output(s), etc., to perform, when activated, one or more its corresponding functions and may further include inferred coupling to one or more other items. As may still further be used herein, the term “associated with”, includes direct and/or indirect coupling of separate items and/or one item being embedded within another item.

As may be used herein, the term “compares favorably”, indicates that a comparison between two or more items, signals, etc., provides a desired relationship. For example, when the desired relationship is that signal 1 has a greater magnitude than signal 2, a favorable comparison may be achieved when the magnitude of signal 1 is greater than that of signal 2 or when the magnitude of signal 2 is less than that of signal 1. As may be used herein, the term “compares unfavorably”, indicates that a comparison between two or more items, signals, etc., fails to provide the desired relationship.

As may also be used herein, the terms “processing module”, “processing circuit”, “processor”, and/or “processing unit” may be a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on hard coding of the circuitry and/or operational instructions. The processing module, module, processing circuit, and/or processing unit may be, or further include, memory and/or an integrated memory element, which may be a single memory device, a plurality of memory devices, and/or embedded circuitry of another processing module, module, processing circuit, and/or processing unit. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that if the processing module, module, processing circuit, and/or processing unit includes more than one processing device, the processing devices may be centrally located (e.g., directly coupled together via a wired and/or wireless bus structure) or may be distributedly located (e.g., cloud computing via indirect coupling via a local area network and/or a wide area network). Further note that if the processing module, module, processing circuit, and/or processing unit implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory and/or memory element storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. Still further note that, the memory element may store, and the processing module, module, processing circuit, and/or processing unit executes, hard coded and/or operational instructions corresponding to at least some of the steps and/or functions illustrated in one or more of the Figures. Such a memory device or memory element can be included in an article of manufacture.

One or more embodiments have been described above with the aid of method steps illustrating the performance of specified functions and relationships thereof. The boundaries and sequence of these functional building blocks and method steps have been arbitrarily defined herein for convenience of description. Alternate boundaries and sequences can be defined so long as the specified functions and relationships are appropriately performed. Any such alternate boundaries or sequences are thus within the scope and spirit of the claims. Further, the boundaries of these functional building blocks have been arbitrarily defined for convenience of description. Alternate boundaries could be defined as long as the certain significant functions are appropriately performed. Similarly, flow diagram blocks may also have been arbitrarily defined herein to illustrate certain significant functionality.

To the extent used, the flow diagram block boundaries and sequence could have been defined otherwise and still perform the certain significant functionality. Such alternate definitions of both functional building blocks and flow diagram blocks and sequences are thus within the scope and spirit of the claims. One of average skill in the art will also recognize that the functional building blocks, and other illustrative blocks, modules and components herein, can be implemented as illustrated or by discrete components, application specific integrated circuits, processors executing appropriate software and the like or any combination thereof.

In addition, a flow diagram may include a “start” and/or “continue” indication. The “start” and “continue” indications reflect that the steps presented can optionally be incorporated in or otherwise used in conjunction with other routines. In this context, “start” indicates the beginning of the first step presented and may be preceded by other activities not specifically shown. Further, the “continue” indication reflects that the steps presented may be performed multiple times and/or may be succeeded by other activities not specifically shown. Further, while a flow diagram indicates a particular ordering of steps, other orderings are likewise possible provided that the principles of causality are maintained.

The one or more embodiments are used herein to illustrate one or more aspects, one or more features, one or more concepts, and/or one or more examples. A physical embodiment of an apparatus, an article of manufacture, a machine, and/or of a process may include one or more of the aspects, features, concepts, examples, etc. described with reference to one or more of the embodiments discussed herein. Further, from figure to figure, the embodiments may incorporate the same or similarly named functions, steps, modules, etc. that may use the same or different reference numbers and, as such, the functions, steps, modules, etc. may be the same or similar functions, steps, modules, etc. or different ones.

Unless specifically stated to the contra, signals to, from, and/or between elements in a figure of any of the figures presented herein may be analog or digital, continuous time or discrete time, and single-ended or differential. For instance, if a signal path is shown as a single-ended path, it also represents a differential signal path. Similarly, if a signal path is shown as a differential path, it also represents a single-ended signal path. While one or more particular architectures are described herein, other architectures can likewise be implemented that use one or more data buses not expressly shown, direct connectivity between elements, and/or indirect coupling between other elements as recognized by one of average skill in the art.

The term “module” is used in the description of one or more of the embodiments. A module implements one or more functions via a device such as a processor or other processing device or other hardware that may include or operate in association with a memory that stores operational instructions. A module may operate independently and/or in conjunction with software and/or firmware. As also used herein, a module may contain one or more sub-modules, each of which may be one or more modules.

As may further be used herein, a computer readable memory includes one or more memory elements. A memory element may be a separate memory device, multiple memory devices, or a set of memory locations within a memory device. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. The memory device may be in a form a solid state memory, a hard drive memory, cloud memory, thumb drive, server memory, computing device memory, and/or other physical medium for storing digital information.

While particular combinations of various functions and features of the one or more embodiments have been expressly described herein, other combinations of these features and functions are likewise possible. The present disclosure is not limited by the particular examples disclosed herein and expressly incorporates these other combinations. 

What is claimed is:
 1. A method for execution by one or more processing modules of one or more computing devices, the method comprises: encoding data to produce a plurality of sets of encoded data slices; generating one or more write slice requests, wherein each of the write slice requests correspond to one or more sets of encoded data slices of the plurality of sets of encoded data slices; outputting the one or more write slice requests to a set of distributed storage and task execution units; for each distributed storage and task execution unit of the set of distributed storage and task execution units, determining a data ingest rate of a set of data ingest rates; determining a write threshold number of distributed storage and task execution units of the set of distributed storage and task execution units based on the set of data ingest rates; determining a transmit data rate; generating a write threshold number of write slice requests to a write threshold number of distributed storage and task execution units; and inputting the write threshold number of write slice requests to the write threshold number of distributed storage and task execution units of the set of distributed storage and task execution units.
 2. The method of claim 1 further comprises: facilitating rebuilding the encoded data slices of the one or more sets of encoded data slices not included in the write threshold number of write slice requests to the distributed storage and task execution units not selected as part of the write threshold number of distributed storage and task execution units.
 3. The method of claim 1, wherein the determining a data ingest rate of a set of data ingest rates is based on at least one of an estimated reliability level for data storage, a reliability level threshold, an estimated access speed, a lowest access speed of the write threshold number of distributed storage and task execution units, a speed threshold, an access capability estimator, a predetermination, an estimated rebuilding impact, or a rebuilding impact threshold.
 4. The method of claim 1, wherein the determining a data ingest rate of a set of data ingest rates is based on at least one of a query, a test, monitoring loading levels, a list, or receiving loading information as part of an access request.
 5. The method of claim 1, wherein the transmit data rate is determined, such that a data ingress rate plus an aggregate of a plurality of data loading levels is less than the data ingress rate of the set of distributed storage and task execution units.
 6. The method of claim 1, wherein the write threshold number of distributed storage and task execution units of the set of distributed storage and task execution units equals at least the minimum number of encoded data slices required for rebuilding encoded data slices not written to corresponding distributed storage and task execution units.
 7. A dispersed storage module comprises: a first module, when operable within a computing device, causes the computing device to: encode data to produce a plurality of sets of encoded data slices; generate one or more write slice requests, wherein each of the write slice requests correspond to one or more sets of encoded data slices of the plurality of sets of encoded data slices; and output the one or more write slice requests to a set of distributed storage and task execution units; a second module, when operable within the computing device, causes the computing device to: determine a data ingest rate of a set of data ingest rates for each distributed storage and task execution unit of the set of distributed storage and task execution units; and determine a write threshold number of distributed storage and task execution units of the set of distributed storage and task execution units based on the set of data ingest rates; a third module, when operable within the computing device, causes the computing device to: determine a transmit data rate; generate a write threshold number of write slice requests to the write threshold number of distributed storage and task execution units for each remaining set of encoded data slices of the plurality of sets of encoded data slices; and a fourth module, when operable within the computing device, causes the computing device to: input the write threshold number of write slice requests to the write threshold number of distributed storage and task execution units of the set of distributed storage and task execution units.
 8. The dispersed storage module of claim 7 further comprises: a fifth module, when operable within the computing device, causes the computing device to: facilitate rebuilding the encoded data slices of the one or more sets of encoded data slices not included in the write threshold number of write slice requests.
 9. The dispersed storage module of claim 7, wherein the second module, when operable within the computing device, causes the computing device to: determine a data ingest rate of a set of data ingest rates based on at least one of an estimated reliability level for data storage, a reliability level threshold, an estimated access speed, a lowest access speed of the write threshold number of distributed storage and task execution units, a speed threshold, an access capability estimator, a predetermination, an estimated rebuilding impact, or a rebuilding impact threshold.
 10. The dispersed storage module of claim 7, wherein the second module, when operable within the computing device, causes the computing device to: determine a data ingest rate of a set of data ingest rates based on at least one of a query, a test, monitoring loading levels, a list, or receiving loading information as part of an access request.
 11. A method for execution by one or more processing modules of one or more computing devices, the method comprises: determining to access a set of distributed storage and task execution units; determining a data loading level for each distributed storage and task execution unit of the set of distributed storage and task execution units; determining an aggregate data access rate for the set of distributed storage and task execution units based on the data loading level for the distributed storage and task execution units of the set of distributed storage and task execution units; determining a data access threshold number of distributed storage and task execution units based on the aggregate data access rate; and based on the data access threshold number, generating slice access requests.
 12. The method of claim 11, wherein the data access threshold number of distributed storage and task execution units equals at least the minimum number of slices required for rebuilding encoded data slices.
 13. The method of claim 11, wherein the data access rate is determined such that the data access rate plus an aggregate of a plurality of data loading levels is less than a data access capability level of the set of distributed storage and task execution units.
 14. The method of claim 11, wherein the determining to access a set of distributed storage and task execution units based on at least one of receiving a retrieval request, receiving a rebuilding request, or receiving a storage request.
 15. The method of claim 11, wherein the data loading level for each distributed storage and task execution unit of the set of distributed storage and task execution units includes input and output loading metrics for access to each distributed storage and task execution unit of the set of distributed storage and task execution units.
 16. The method of claim 11, wherein the data loading level for each distributed storage and task execution unit of the set of distributed storage and task execution units is based on at least one of a query, a test, monitoring loading levels, receiving a list, or receiving loading information as part of an access request.
 17. The method of claim 11, wherein the data loading level for each distributed storage and task execution unit of the set of distributed storage and task execution units is based on at least one of an estimated reliability level for data storage, a reliability level threshold, an estimated data access speed, a lowest access speed of the data access threshold number of distributed storage and task execution units, a speed threshold, a data access capability estimator, a predetermination, an estimated rebuilding impact, or a rebuilding impact threshold. 